Bits: July 20, 2004
iTunes 100 million song contest

Apple recently had a
contest
to give away a 17" laptop and a coupon worth
10,000 song downloads to
the person who bought the 100 millionth song from the iTunes
Music Store.
They also gave away 50 iPods (1 at every 100,000 from
95 million to 100 million). They displayed the current
number of songs purchased (updated periodically) and I
started keeping track of it to see if I could try buying
some songs at the right time
to give me a chance at winning. Below is a
plot of the data I recorded over a few days, including a
line fit based on the data before 99.9 million that gave
me a general idea when it would hit 100 million. I knew
this would be off, but at least I knew that I would need
to stay up Sunday night. The graph also shows how song
buying changes over the course of a day (the vertical dotted
lines mark midnight eastern time). Looking at the slope, it
shows that the iTunes Music Store sells about 6.3 songs per
second on average.

Of course, the above plot wouldn't let me know when I should
actually buy songs, since the buying accelerated at the end.
Below is a zoom in on the end of the graph above. It has
another line fit that includes the data after the last iPod
was won at 99.9 million until I started buying music. It
shows that there was a 10,000 song jump around 99.9 million
when the iPod was won. Accounting for this, the red star on
the line fit shows when the song count should hit 100 million
- 10,000 = 99.99 million.
This analysis predicted that the 100 millionth song
would be purchased at 1:33 am. According to Apple, it was
actually purchased at 1:21 am. From my graph, it looks like
the winning song was purchased at 1:23, but all my data points
are delayed a bit.

Regardless, I was purchasing songs around the time of the winner,
so I guess I did everything I could. Given that they were selling
almost 100 songs per second at that point, I shouldn't be disappointed
that I didn't win. Oh well, at least I got some good music out of
the deal.